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Does the car start fairy easy during the summer time with 1 day of it standing and not so easy start during the cold winter months?
or is it same in winter and summer?
Does the car start fairy easy during the summer time with 1 day of it standing and not so easy start during the cold winter months?
or is it same in winter and summer?
On my car it does not make any difference. Starts up straight away after priming. Summer a bit easier than winter as it would be with any other car with no issues. On winter it does start ok if primed, nothing worrying, max one turn or less.
virgisr, can you smell fuel around engine or as you approach the car?
2 winters ago had really long crank times and played the game of key on and wait for lift pump to supply hp pump.
Having been through this and replaced a couple of injectors after leak-down test results, here's what I can offer.
Since nothing goes together for me correctly the first time, I observed the problem of leaks at the little o-rings (under the fuel return line connections).
If they allow air in at rest, the fuel siphons back down out of system. At least it seems that way.
After finding leaked fuel and replacing o-ring(s), car started much better, almost first rotation.
i did not find any symptoms of leaks, no smell as well. I probably should get to the bottom of this one day. Replace them two injectors and hope it fixes the problem.
As situation is not getting any worse, i am kind of used to priming fuel. Not the best solution, but works for now.
Thanks for the input.
Does the car start fairy easy during the summer time with 1 day of it standing and not so easy start during the cold winter months?
or is it same in winter and summer?
I don't know because I only realized the issue after the "Bluetec field measure" campaign/recall. Along with installing new exhaust components, they also reflashed the software.
Before when I start, the fuel pump turns on for 1 second, and then the engine starts cranking. After the software reflash, the engine cranks right away when I press "start".
Naturally the way it started would have masked the issue. And I think this issue must have been going on for a while.
Short Update: new fuel filter in, issue still not resolved.
Long Update:
New filter is definetly better. With the old filter, when I blow into either inlet/outlet port, air can come out the other side. Blowing from the inlet did take less effort than from the outlet though. With the new one, I can't blow any air through.
Google said human lungs are only capable of 2psi of pressure. So change your fuel filter. It's good maintenence anyway.
The problem is simple to understand - the fuel between LPP and HPP does not hold pressure. I am suspecting the fuel return line now. And it's also the easiest and cheapest to replace.
Also possible - leaking injector nozzles, or bad low pressure pump. Does anybody know how to test them?
Yes, in your diagram the leak I described is at the injector end of the return line.
If you pull off the engine cover and the sound absorbing foam covers from between the injector lines you would likely see and smell fuel.
Maybe a puddle in the valley in the valve/cam cover. It would collect at the back / downhill.
The o-rings can get hard and leak, they are under the lip of the fuel return on each injector, and the return line at this point is shaped like a wye (Y).
Gently rotate the ring on the connector to test it's not sticking. You can lube it with WD40 or similar.
Then with your fingers no tool/prying try to pull the ring upward, it should release with a snap.
These retaining rings/snaps get brittle like all the black plastic bits around the motor.
If the injector is leaking with the black death carbon buildup it makes them even more likely to break.
I suppose it's possible that it could leak only air into the return line at rest, without also leaking fuel under pressure.
But doubtful
/
I would stop if I don't see evidence of fuel leak from any return line fitting.
The wye shaped line uses a circlip to connect to the rest of the return line, near the hp fuel pump. Is also possible to leak there. Follow your nose
Yes, in your diagram the leak I described is at the injector end of the return line.
If you pull off the engine cover and the sound absorbing foam covers from between the injector lines you would likely see and smell fuel.
Maybe a puddle in the valley in the valve/cam cover. It would collect at the back / downhill.
The o-rings can get hard and leak, they are under the lip of the fuel return on each injector, and the return line at this point is shaped like a wye (Y).
Gently rotate the ring on the connector to test it's not sticking. You can lube it with WD40 or similar.
Then with your fingers no tool/prying try to pull the ring upward, it should release with a snap.
These retaining rings/snaps get brittle like all the black plastic bits around the motor.
If the injector is leaking with the black death carbon buildup it makes them even more likely to break.
I suppose it's possible that it could leak only air into the return line at rest, without also leaking fuel under pressure.
But doubtful
/
I would stop if I don't see evidence of fuel leak from any return line fitting.
The wye shaped line uses a circlip to connect to the rest of the return line, near the hp fuel pump. Is also possible to leak there. Follow your nose
I actually checked the fuel return line when I did the filter. I believe the ML and R have different return line connections.
No smell on mine, and no sign of external leaks.
One weird thing on mine though - when I disconnect the return line from all six injectors, and crank the engine, to see if any injector squirts more fuel than others at the return ports. Diesel spits out from the return line at all six open connections.
I always thought the return line should be one-way, ie. diesel only goes from injector to the metal line, not the other way around. But I am not 100% sure on this. That's why I didn't jump on getting it replaced.
If you take a look at diagram above, the injectors return line goes back to low pressure line, who operates at about 70 psi. Meaning there is always pressure going both ways.
Suppose the Tee making the connection is calibrated to control back pressure for injectors. A note for those who broke OE plastic Tee and replaced it with aftermarket metal piece.
Injector spill valves -> injector return lines -> LP line
Under normal operation (nothing disconnected) the excess (HP) fuel would always return from injectors to LP line.
It's only coming out of the LP pipe because it's disconnected.
The only check valve needed between them is inside the injector. (the spill valve)
I don't really trust those plastic connectors, the style they used on the OM648 seemed better to me.
After posting on this thread a couple of times, I smell fuel when I get in my car, again. I know where to look anyway.
i did not find any symptoms of leaks, no smell as well. I probably should get to the bottom of this one day. Replace them two injectors and hope it fixes the problem.
As situation is not getting any worse, i am kind of used to priming fuel. Not the best solution, but works for now.
Thanks for the input.
Hi i bought 320 cdi and have a same problem, my injector maybe was repair by previus owner, but i also check them, dont leak back in the first 10 sec, when try to sart up, so the hight pressure shoud be ok.
i try to manually add 12 v to glow plugs, and my car start at first. My relay dont add 12 v to glow plags in summer, it is normal?
,..... My relay dont add 12 v to glow plags in summer, it is normal?
When I did not check electrical part, those newer diesels start really good.
I did have GP relay failure and in 50F weather the engine would fire in about 3 seconds of cranking.
I live in warm climate, so on Sprinter, who has turn-ignition, I just turn it to start without any wait.
But couple days ago I was in the mountains and with 29F I did the same, before the thought come to my mind.
The engine maybe not started on 1st cylinder, how it usually do, but 1 engine turn was all it took.
My other Bluetecs do have keyless go and in warm weather they turn right away.
But a month ago I had my GLE in about 5F, so when I push the start button, there was like 3 seconds delay before computer turned the starter on.
3 seconds is all it takes.
i did not find any symptoms of leaks, no smell as well. I probably should get to the bottom of this one day. Replace them two injectors and hope it fixes the problem.
As situation is not getting any worse, i am kind of used to priming fuel. Not the best solution, but works for now.
Thanks for the input.
I’m pulling this thread out of the trenches as I have a similar situation, although for now it seems resolved.
During the winter, in Poland, with temperatures around -5/5 degrees Celsius the car used to start up perfectly, without any hesitation. A month ago, after coming to Italy, with a subsequent increase of temperature of about 10 degrees, the car started to act up.
After a night of sitting, when I start it up, it cranks 2/3 seconds (longer than on average), I don't turn the engine on before the glow plugs light goes out or anything.
Right now unfortunately I don't have any diagnostic tool to check the fuel pressure.
For now I replaced 2 hoses, visible in the images attached that were absolutely leaking, perhaps the long trip worsened the leak and allowed some air in the system.
Line from tank to fuel filter, new on the left, old on the right.
Return from pump to tank, new on the left, old on the right.
did it make difference? the replaced hoses? thanks.
I replaced them yesterday, this morning it started perfectly but I need a couple of days to be sure 100%.
If someone will be going to replace those 2 hoses I can write a couple of advices, as to do a good job and use the proper clic clamps it's necessary to remove the power steering reservoir and buy a specific set of pliers.
If what I did won't resolve the problem, the hose coming from the rail back to the tank is yet to be replaced, number 35 in the previous schematics. Only thing that does make sense now is to go step by step.
I hope that by Sunday I'll have some good perhaps definitive answers.
i will be looking into changing them on my merc. The hoses on mine are not the best shape, but no leaks, so i did not think i would need replacing them. I still have delayed startup after its parked longer period, but overcoming it with letting fuel prime for longer with ignition on.
Let us know how it goes. Another question, you bought the hoses from mercedes? on pictures looks like its shaped as the original.
In the R I would have to remove the engine from the bay to clamp those hoses, there are perhaps 5 cm of clearance and if the pliers do not have rotating heads it is basically impossible to reach them, at the beginning I was also going to buy the cheaper ones but soon realized it would be a waste of money and time.
Also beta is an excellent brand.
I'll take a photo later of how tight that spot is.
I would have to remove the engine from the bay to clamp those hoses,
Like I said, I feel bad for you guys. I may find at some later date I have the same problem. I only bought them to change the fuel filter. (I was sorely tempted to cut the clamps off and replace them with clamps you can remove with a screw driver...)
Like I said, I feel bad for you guys. I may find at some later date I have the same problem. I only bought them to change the fuel filter. (I was sorely tempted to cut the clamps off and replace them with clamps you can remove with a screw driver...)
I am still tempted to do that. Any reason not to? Ya can literally buy a foot of fuel line at auto parts store and the 4 clamps and be good to go.
10-25-2022, 07:25 AM
